BackgroundDried blood spots (DBS) are a convenient tool to enable diagnostic testing for viral diseases due to transport, handling and logistical advantages over conventional venous blood sampling. A better understanding of the performance of serological testing for hepatitis C (HCV) and hepatitis B virus (HBV) from DBS is important to enable more widespread use of this sampling approach in resource limited settings, and to inform the 2017 World Health Organization (WHO) guidance on testing for HBV/HCV.MethodsWe conducted two systematic reviews and meta-analyses on the diagnostic accuracy of HCV antibody (HCV-Ab) and HBV surface antigen (HBsAg) from DBS samples compared to venous blood samples. MEDLINE, EMBASE, Global Health and Cochrane library were searched for studies that assessed diagnostic accuracy with DBS and agreement between DBS and venous sampling. Heterogeneity of results was assessed and where possible a pooled analysis of sensitivity and specificity was performed using a bivariate analysis with maximum likelihood estimate and 95% confidence intervals (95%CI). We conducted a narrative review on the impact of varying storage conditions or limits of detection in subsets of samples. The QUADAS-2 tool was used to assess risk of bias.ResultsFor the diagnostic accuracy of HBsAg from DBS compared to venous blood, 19 studies were included in a quantitative meta-analysis, and 23 in a narrative review. Pooled sensitivity and specificity were 98% (95%CI:95%–99%) and 100% (95%CI:99–100%), respectively. For the diagnostic accuracy of HCV-Ab from DBS, 19 studies were included in a pooled quantitative meta-analysis, and 23 studies were included in a narrative review. Pooled estimates of sensitivity and specificity were 98% (CI95%:95–99) and 99% (CI95%:98–100), respectively. Overall quality of studies and heterogeneity were rated as moderate in both systematic reviews.ConclusionHCV-Ab and HBsAg testing using DBS compared to venous blood sampling was associated with excellent diagnostic accuracy. However, generalizability is limited as no uniform protocol was applied and most studies did not use fresh samples. Future studies on diagnostic accuracy should include an assessment of impact of environmental conditions common in low resource field settings. Manufacturers also need to formally validate their assays for DBS for use with their commercial assays.
BackgroundThe detection and quantification of hepatitis B (HBV) DNA and hepatitis C (HCV) RNA in whole blood collected on dried blood spots (DBS) may facilitate access to diagnosis and treatment of HBV and HCV infection in resource-poor settings. We evaluated the diagnostic performance of DBS compared to venous blood samples for detection and quantification of HBV-DNA and HCV-RNA in two systematic reviews and meta-analyses on the diagnostic accuracy of HBV DNA and HCV RNA from DBS compared to venous blood samples.MethodsWe searched MEDLINE, Embase, Global Health, Web of Science, LILAC and Cochrane library for studies that assessed diagnostic accuracy with DBS. Heterogeneity was assessed and where appropriate pooled estimates of sensitivity and specificity were generated using bivariate analyses with maximum likelihood estimates and 95% confidence intervals. We also conducted a narrative review on the impact of varying storage conditions or different cut-offs for detection from studies that undertook this in a subset of samples. The QUADAS-2 tool was used to assess risk of bias.ResultsIn the quantitative synthesis for diagnostic accuracy of HBV-DNA using DBS, 521 citations were identified, and 12 studies met the inclusion criteria. Overall quality of studies was rated as low. The pooled estimate of sensitivity and specificity for HBV-DNA was 95% (95% CI: 83–99) and 99% (95% CI: 53–100), respectively. In the two studies that reported on cut-offs and limit of detection (LoD) – one reported a sensitivity of 98% for a cut-off of ≥2000 IU/ml and another reported a LoD of 914 IU/ml using a commercial assay. Varying storage conditions for individual samples did not result in a significant variation of results. In the synthesis for diagnostic accuracy of HCV-RNA using DBS, 15 studies met the inclusion criteria, and this included six additional studies to a previously published review. The pooled sensitivity and specificity was 98% (95% CI:95–99) and 98% (95% CI:95–99.0), respectively. Varying storage conditions resulted in a decrease in accuracy for quantification but not for reported positivity.ConclusionsThese findings show a high level of diagnostic performance for the use of DBS for HBV-DNA and HCV-RNA detection. However, this was based on a limited number and quality of studies. There is a need for development of standardized protocols by manufacturers on the use of DBS with their assays, as well as for larger studies on use of DBS conducted in different settings and with varying storage conditions.
Objectives To investigate whether Staphylococcus aureus bloodstream infection (SAB) patients at high risk for complications or relapse benefit from combination therapy with adjunctive rifampicin or fosfomycin. Methods In this post hoc analysis, SAB patients with native valve infective endocarditis, osteoarticular infections or implanted foreign devices were included. The co-primary endpoints were all-cause 90 day mortality and death or SAB-related late complications within 180 days. To overcome treatment selection bias and account for its time dependence, inverse probability of treatment weights were calculated and included in marginal structural Cox proportional hazard models (MSCMs). Results A total of 578 patients were included in the analysis, of which 313 (54%) received combination therapy with either rifampicin (n = 242) or fosfomycin (n = 58). In the multivariable MSCM, combination therapy was associated with a better outcome, that is, a lower rate of death or SAB-related late complications within 180 days (HR 0.65, 95% CI 0.46–0.92). This beneficial effect was primarily seen in patients with implanted foreign devices, in which combination therapy was associated with a lower rate of death or SAB-related late complications within 180 days (HR 0.53, 95% CI 0.35–0.79) and a lower 90 day mortality (HR 0.57, 95% CI 0.36–0.91). Upon agent-specific stratification, we found no significant differences in outcomes between combination therapy containing rifampicin and fosfomycin; however, the number of patients in most subgroups was not large enough to draw firm conclusions. Conclusions In patients with implanted foreign devices, combination therapy was associated with a better long-term outcome. Larger prospective studies are needed to validate these findings.
Gram-negative bacteria partly rely on efflux pumps to facilitate growth under stressful conditions and to increase resistance to a wide variety of commonly used drugs. In recent years E. coli ST131 has emerged as a major cause of extraintestinal infection frequently exhibiting an MDR phenotype. The contribution of efflux to MDR in emerging E. coli MDR clones however, is not well studied. We characterized strains from an international collection of clinical MDR-E. coli isolates by MIC testing with and without the addition of the AcrAB-TolC efflux inhibitor 1-(1-naphthylmethyl)-piperazine (NMP). MIC data for 6 antimicrobial agents and their reversion by NMP were analyzed by Principal Component Analysis (PCA). PCA revealed a group of 17/34 MDR-E. coli exhibiting increased susceptibility to treatment with NMP suggesting an enhanced contribution of efflux pumps to antimicrobial resistance in these strains (termed “enhanced efflux phenotype” [EEP]). Only 1/17 EEP strains versus 12/17 non-EEP MDR strains belonged to the ST131 clonal group. Whole-genome sequencing revealed marked differences in efflux-related genes between EEP and control strains, with the majority of notable amino-acid substitutions occurring in AcrR, MarR and SoxR. qRT-PCR of multiple efflux-related genes showed significant overexpression of the AcrAB-TolC-system in EEP strains, whereas in the remaining strains we found enhanced expression of alternative efflux proteins. We conclude that a proportion of MDR E. coli exhibit an EEP, which is linked to an overexpression of the AcrAB-TolC-efflux-pump and a distinct array of genomic variations. Members of ST131, although highly successful, are less likely to exhibit the EEP.
Background: Patients with asplenia have a significantly increased lifelong risk of severe invasive infections, particular post-splenectomy sepsis (PSS). Clear preventive measures have been described in the literature, but previous studies found poor implementation of prevention recommendations. Aim of the study is to improve the adherence to guideline-based preventive measures and thereby reduce the incidence of PSS by a novel telephone-delivered intervention that involves both patients and their physicians. Methods: A prospective controlled, two-armed historical control group design is used to evaluate the new intervention compared to usual care. The intervention for patients includes both educational aspects and, building on the Health Action Process Approach (HAPA), intervention components that promote motivation and planning of preventive measures. For physicians the intervention is primarily information-based. The primary outcome, the adherence to preventative measures, is indicated by a study-specific 'Preventing PSS-score' (PrePSS-score), which is assessed at baseline and at 6-months follow-up. Secondary outcomes include, amongst others, patient self-efficacy and action-planning, asplenia-specific health literacy, general self-management and asplenia-specific self-management. In a process-evaluating part of the study interview-data on patients' and physicians' evaluation of the intervention will be gathered. Discussion: This trial will provide evidence about the effectiveness of the novel prevention intervention for asplenic patients. If demonstrated beneficial, the intervention manual will be made publicly available to enable implementation in practice. The experience gained within this trial may also be valuable for prevention strategies in patients with other diseases.
Few guidelines for health care of refugees exist in Germany. Screening as a part of initial health checks as well as general organisation of early health care for refugees is very heterogenous across different regions. Current experience will be relevant to develop integrated health care models. Prevention and care of infectious diseases are an important part of early health care for refugees, even if non-communicable diseases and mental health conditions should also be considered in every effort to design early health care models. We are presenting a pragmatic review of current evidence for prevention and care of tuberculosis, HIV, chronic viral hepatitis and other infectious diseases. More evidence is needed to assess morbidity and efficacy of early health care interventions and integrated care models in refugees.
ObjectiveTo explore patients’ with asplenia and general practitioners’ (GPs) (1) perceptions of a novel,Health Action Process Approach(HAPA)-based, educational intervention which targets to increase adherence to post-splenectomy sepsis (PSS) prevention measures and (2) their experience in implementing prevention measures following this intervention.DesignA process evaluation conducted on average 3.5 (for patients) and 3.8 (for GPs) months after the intervention between January 2020 and April 2021 individually by means of semi-structured guideline-based telephone interviews. Data was analysed using qualitative content analysis.ParticipantsVolunteer subsample of N=25 patients with asplenia and N=8 GPs who received the intervention. Inclusion criteria were met by prior participation in the intervention (German-speaking, of full age and insured by the cooperating health insurance). Patient selection was done by purposeful selection aiming at maximum variability in terms of adherence to preventative measures prior to intervention participation. Participating GPs are a non-purposeful selected convenience sample. For reasons of data protection, no personal data was collected.ResultsThe intervention was positively evaluated and its personal relevancy for patients and for the GPs’ professional work became apparent. The intervention promoted risk awareness, intention to action, action planning and subsequently, improved adherence to preventative measures. Helpful factors for implementation among the patients were social support by relatives and GPs. Barriers to adherence identified in both groups can be divided into patient-attributed (eg, comorbidities), doctor-related (eg, lack of knowledge or support) as well as contextual factors (eg, vaccine supply constraints).ConclusionsOur findings indicate a patient and GP perceived benefit of the intervention, but still identify prevailing barriers to implementation. In a further step, a quantitative evaluation of the intervention will be conducted and recommendations for integrating the intervention in usual care will be made.Trial registration numberDRKS00015238.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.